Is there any keyboard shortcut to paste into Kate from the mouse-highlight clipboard? I tried Ctrl-Shift-Insert and a few other likely cases, but none of them worked.

Thanks.

if you set Klipper to sync contents of clipboard and selection ctrl+v will work, obviously if you want to keep the 2 selections separate this is not acceptable

The default is supposed to be ctrl+shft+ins but it doesn't work me either and assigning a shortcut in systemsettings didn't work either for me, guessing a bug

Thank you. I do need the two clipboards to be separate, so I'll file an issue. Thanks!

You could create some magic script probably involving xclip and xdotool, if you really wanted, and bind that to a key. But I'm not sure it's worth it.